RESUMEN
This article summarises the objectives, methodology and initial conclusions of the project "Commitment to Quality of the Spanish Scientific Societies", coordinated by the Ministry of Health, Social Services and Equality, the Spanish Society of Internal Medicine and the Aragon Institute of Health Sciences, in which 48 scientific societies participate. This project's objectives are to decrease the use of unnecessary medical interventions, which are those that have shown no efficacy, have little or questionable effectiveness or are not cost-effective; decrease variability in clinical practice; promote the commitment among physicians and patients to properly use healthcare resources; and to promote clinical safety. The document includes 135 final recommendations for what not to do, prepared by 30 Spanish scientific societies.